MINOR: listener: now use a generic add_listener() function

With the removal of the family-specific port setting, all protocol had
exactly the same implementation of ->add(). A generic one was created
with the name "default_add_listener" so that all other ones can now be
removed. The API was slightly adjusted so that the protocol and the
listener are passed instead of the listener and the port.

Note that all protocols continue to provide this ->add() method instead
of routinely calling default_add_listener() from create_listeners(). This
makes sure that any non-standard protocol will still be able to intercept
the listener addition if needed.

This could be backported to 2.3 along with the few previous patches on
listners as a pure code cleanup.

(cherry picked from commit d1f250f87b8850f24456e62140509e612f8b3415)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/include/haproxy/listener.h b/include/haproxy/listener.h
index 722a9ea..8200395 100644
--- a/include/haproxy/listener.h
+++ b/include/haproxy/listener.h
@@ -124,6 +124,13 @@
  */
 void listener_release(struct listener *l);
 
+/* This function adds the specified <listener> to the protocol <proto>. It
+ * does nothing if the protocol was already added. The listener's state is
+ * automatically updated from LI_INIT to LI_ASSIGNED. The number of listeners
+ * for the protocol is updated. This must be called with the proto lock held.
+ */
+void default_add_listener(struct protocol *proto, struct listener *listener);
+
 /* default function used to unbind a listener. This is for use by standard
  * protocols working on top of accepted sockets. The receiver's rx_unbind()
  * will automatically be used after the listener is disabled if the socket is
diff --git a/include/haproxy/protocol-t.h b/include/haproxy/protocol-t.h
index 2a59950..494f95d 100644
--- a/include/haproxy/protocol-t.h
+++ b/include/haproxy/protocol-t.h
@@ -88,7 +88,7 @@
 	int sock_prot;					/* socket protocol, as passed to socket() */
 
 	/* functions acting on the listener */
-	void (*add)(struct listener *l, int port);      /* add a listener for this protocol and port */
+	void (*add)(struct protocol *p, struct listener *l); /* add a listener for this protocol */
 	int (*listen)(struct listener *l, char *errmsg, int errlen); /* start a listener */
 	void (*enable)(struct listener *l);             /* enable receipt of new connections */
 	void (*disable)(struct listener *l);            /* disable receipt of new connections */
diff --git a/src/listener.c b/src/listener.c
index 7689ceb..87b2bd2 100644
--- a/src/listener.c
+++ b/src/listener.c
@@ -323,6 +323,21 @@
 		HA_RWLOCK_WRUNLOCK(PROXY_LOCK, &px->lock);
 }
 
+/* This function adds the specified <listener> to the protocol <proto>. It
+ * does nothing if the protocol was already added. The listener's state is
+ * automatically updated from LI_INIT to LI_ASSIGNED. The number of listeners
+ * for the protocol is updated. This must be called with the proto lock held.
+ */
+void default_add_listener(struct protocol *proto, struct listener *listener)
+{
+	if (listener->state != LI_INIT)
+		return;
+	listener_set_state(listener, LI_ASSIGNED);
+	listener->rx.proto = proto;
+	LIST_ADDQ(&proto->receivers, &listener->rx.proto_list);
+	proto->nb_receivers++;
+}
+
 /* default function called to suspend a listener: it simply passes the call to
  * the underlying receiver. This is find for most socket-based protocols. This
  * must be called under the listener's lock. It will return non-zero on success,
@@ -616,13 +631,13 @@
 		l->rx.fd = fd;
 
 		memcpy(&l->rx.addr, ss, sizeof(*ss));
-		if (proto->fam.set_port)
-			proto->fam.set_port(&l->rx.addr, port);
+		if (proto->fam->set_port)
+			proto->fam->set_port(&l->rx.addr, port);
 
 		MT_LIST_INIT(&l->wait_queue);
 		listener_set_state(l, LI_INIT);
 
-		proto->add(l, port);
+		proto->add(proto, l);
 
 		if (fd != -1)
 			l->rx.flags |= RX_F_INHERITED;
diff --git a/src/proto_sockpair.c b/src/proto_sockpair.c
index cc92753..fe74ff4 100644
--- a/src/proto_sockpair.c
+++ b/src/proto_sockpair.c
@@ -43,7 +43,6 @@
 #include <haproxy/version.h>
 
 
-static void sockpair_add_listener(struct listener *listener, int port);
 static int sockpair_bind_listener(struct listener *listener, char *errmsg, int errlen);
 static void sockpair_enable_listener(struct listener *listener);
 static void sockpair_disable_listener(struct listener *listener);
@@ -71,7 +70,7 @@
 	.sock_domain = AF_CUST_SOCKPAIR,
 	.sock_type = SOCK_STREAM,
 	.sock_prot = 0,
-	.add = sockpair_add_listener,
+	.add = default_add_listener,
 	.listen = sockpair_bind_listener,
 	.enable = sockpair_enable_listener,
 	.disable = sockpair_disable_listener,
@@ -89,23 +88,6 @@
 
 INITCALL1(STG_REGISTER, protocol_register, &proto_sockpair);
 
-/* Add <listener> to the list of sockpair listeners (port is ignored). The
- * listener's state is automatically updated from LI_INIT to LI_ASSIGNED.
- * The number of listeners for the protocol is updated.
- *
- * Must be called with proto_lock held.
- *
- */
-static void sockpair_add_listener(struct listener *listener, int port)
-{
-	if (listener->state != LI_INIT)
-		return;
-	listener_set_state(listener, LI_ASSIGNED);
-	listener->rx.proto = &proto_sockpair;
-	LIST_ADDQ(&proto_sockpair.receivers, &listener->rx.proto_list);
-	proto_sockpair.nb_receivers++;
-}
-
 /* Enable receipt of incoming connections for listener <l>. The receiver must
  * still be valid.
  */
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index 7c7670a..30a0045 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -49,8 +49,6 @@
 static int tcp_resume_receiver(struct receiver *rx);
 static void tcp_enable_listener(struct listener *listener);
 static void tcp_disable_listener(struct listener *listener);
-static void tcpv4_add_listener(struct listener *listener, int port);
-static void tcpv6_add_listener(struct listener *listener, int port);
 
 /* Note: must not be declared <const> as its list will be overwritten */
 static struct protocol proto_tcpv4 = {
@@ -60,7 +58,7 @@
 	.sock_domain = AF_INET,
 	.sock_type = SOCK_STREAM,
 	.sock_prot = IPPROTO_TCP,
-	.add = tcpv4_add_listener,
+	.add = default_add_listener,
 	.listen = tcp_bind_listener,
 	.enable = tcp_enable_listener,
 	.disable = tcp_disable_listener,
@@ -90,7 +88,7 @@
 	.sock_domain = AF_INET6,
 	.sock_type = SOCK_STREAM,
 	.sock_prot = IPPROTO_TCP,
-	.add = tcpv6_add_listener,
+	.add = default_add_listener,
 	.listen = tcp_bind_listener,
 	.enable = tcp_enable_listener,
 	.disable = tcp_disable_listener,
@@ -712,40 +710,6 @@
 	return err;
 }
 
-/* Add <listener> to the list of tcpv4 listeners, on port <port>. The
- * listener's state is automatically updated from LI_INIT to LI_ASSIGNED.
- * The number of listeners for the protocol is updated.
- *
- * Must be called with proto_lock held.
- *
- */
-static void tcpv4_add_listener(struct listener *listener, int port)
-{
-	if (listener->state != LI_INIT)
-		return;
-	listener_set_state(listener, LI_ASSIGNED);
-	listener->rx.proto = &proto_tcpv4;
-	LIST_ADDQ(&proto_tcpv4.receivers, &listener->rx.proto_list);
-	proto_tcpv4.nb_receivers++;
-}
-
-/* Add <listener> to the list of tcpv6 listeners, on port <port>. The
- * listener's state is automatically updated from LI_INIT to LI_ASSIGNED.
- * The number of listeners for the protocol is updated.
- *
- * Must be called with proto_lock held.
- *
- */
-static void tcpv6_add_listener(struct listener *listener, int port)
-{
-	if (listener->state != LI_INIT)
-		return;
-	listener_set_state(listener, LI_ASSIGNED);
-	listener->rx.proto = &proto_tcpv6;
-	LIST_ADDQ(&proto_tcpv6.receivers, &listener->rx.proto_list);
-	proto_tcpv6.nb_receivers++;
-}
-
 /* Enable receipt of incoming connections for listener <l>. The receiver must
  * still be valid.
  */
diff --git a/src/proto_udp.c b/src/proto_udp.c
index 436f2a0..5ac7b15 100644
--- a/src/proto_udp.c
+++ b/src/proto_udp.c
@@ -45,8 +45,6 @@
 static int udp_resume_receiver(struct receiver *rx);
 static void udp_enable_listener(struct listener *listener);
 static void udp_disable_listener(struct listener *listener);
-static void udp4_add_listener(struct listener *listener, int port);
-static void udp6_add_listener(struct listener *listener, int port);
 
 /* Note: must not be declared <const> as its list will be overwritten */
 static struct protocol proto_udp4 = {
@@ -56,7 +54,7 @@
 	.sock_domain = AF_INET,
 	.sock_type = SOCK_DGRAM,
 	.sock_prot = IPPROTO_UDP,
-	.add = udp4_add_listener,
+	.add = default_add_listener,
 	.listen = udp_bind_listener,
 	.enable = udp_enable_listener,
 	.disable = udp_disable_listener,
@@ -82,7 +80,7 @@
 	.sock_domain = AF_INET6,
 	.sock_type = SOCK_DGRAM,
 	.sock_prot = IPPROTO_UDP,
-	.add = udp6_add_listener,
+	.add = default_add_listener,
 	.listen = udp_bind_listener,
 	.enable = udp_enable_listener,
 	.disable = udp_disable_listener,
@@ -142,34 +140,6 @@
 	return err;
 }
 
-/* Add <listener> to the list of udp4 listeners, on port <port>. The
- * listener's state is automatically updated from LI_INIT to LI_ASSIGNED.
- * The number of listeners for the protocol is updated.
- */
-static void udp4_add_listener(struct listener *listener, int port)
-{
-	if (listener->state != LI_INIT)
-		return;
-	listener_set_state(listener, LI_ASSIGNED);
-	listener->rx.proto = &proto_udp4;
-	LIST_ADDQ(&proto_udp4.receivers, &listener->rx.proto_list);
-	proto_udp4.nb_receivers++;
-}
-
-/* Add <listener> to the list of udp6 listeners, on port <port>. The
- * listener's state is automatically updated from LI_INIT to LI_ASSIGNED.
- * The number of listeners for the protocol is updated.
- */
-static void udp6_add_listener(struct listener *listener, int port)
-{
-	if (listener->state != LI_INIT)
-		return;
-	listener_set_state(listener, LI_ASSIGNED);
-	listener->rx.proto = &proto_udp6;
-	LIST_ADDQ(&proto_udp6.receivers, &listener->rx.proto_list);
-	proto_udp6.nb_receivers++;
-}
-
 /* Enable receipt of incoming connections for listener <l>. The receiver must
  * still be valid.
  */
diff --git a/src/proto_uxst.c b/src/proto_uxst.c
index f558e5f..9c19374 100644
--- a/src/proto_uxst.c
+++ b/src/proto_uxst.c
@@ -42,7 +42,6 @@
 
 static int uxst_bind_listener(struct listener *listener, char *errmsg, int errlen);
 static int uxst_connect_server(struct connection *conn, int flags);
-static void uxst_add_listener(struct listener *listener, int port);
 static void uxst_enable_listener(struct listener *listener);
 static void uxst_disable_listener(struct listener *listener);
 static int uxst_suspend_receiver(struct receiver *rx);
@@ -55,7 +54,7 @@
 	.sock_domain = PF_UNIX,
 	.sock_type = SOCK_STREAM,
 	.sock_prot = 0,
-	.add = uxst_add_listener,
+	.add = default_add_listener,
 	.listen = uxst_bind_listener,
 	.enable = uxst_enable_listener,
 	.disable = uxst_disable_listener,
@@ -135,23 +134,6 @@
 	return err;
 }
 
-/* Add <listener> to the list of unix stream listeners (port is ignored). The
- * listener's state is automatically updated from LI_INIT to LI_ASSIGNED.
- * The number of listeners for the protocol is updated.
- *
- * Must be called with proto_lock held.
- *
- */
-static void uxst_add_listener(struct listener *listener, int port)
-{
-	if (listener->state != LI_INIT)
-		return;
-	listener_set_state(listener, LI_ASSIGNED);
-	listener->rx.proto = &proto_unix;
-	LIST_ADDQ(&proto_unix.receivers, &listener->rx.proto_list);
-	proto_unix.nb_receivers++;
-}
-
 /* Enable receipt of incoming connections for listener <l>. The receiver must
  * still be valid.
  */